The new document dump includes a minute-long video purportedly produced by the NSA and marked “top secret” that details the way the agency can manipulate computers into thinking they are contacting Facebook’s servers, when they are in fact being directed to servers controlled by the NSA. According to the article, the deception involving Facebook was one of several techniques used by the NSA to conduct surveillance on millions of computers.

Associated Press

The video depicts a man using Facebook on a laptop computer. When he attempts to access a Facebook page, an NSA computer detects the request and sends the man data from its own servers disguised as Facebook traffic, a so-called man-on-the-side attack. The man thinks he is downloading his Facebook page, but is in fact also downloading what amounts to a computer virus that siphons information from his computer and sends it to the U.S. government.

A Facebook spokesman said the company hasn’t seen any evidence that the NSA has used the tactic against Facebook users. He said the method described in the video would not work now, since Facebook began using a higher level of security on its site last year. In any case, he said, Facebook isn’t the only company that was vulnerable to such tactics by the NSA.

It’s unclear how many people might have been targeted by the NSA’s Facebook strategy. Based on the video supplied by Snowden, it appears that the NSA was using it against individuals, and not as an indiscriminate data-gathering strategy. Citing Snowden documents, The Intercept says the NSA hopes to target millions of individuals.

The U.S. government – either through the FBI or NSA — has long used such hacker techniques to go after specific targets. Posing as a Facebook server – or that of any other social network – doesn’t require cooperation from the tech company.

In a statement, the NSA said it monitors communications “exclusively where there is a foreign intelligence or counterintelligence purpose” and that “all of NSA’s operations are strictly conducted under the rule of law.”

In an additional statement Thursday, the NSA denied the thrust of the Intercept story. “Recent media reports that allege NSA has infected millions of computers around the world with malware, and that NSA is impersonating U.S. social media or other websites, are inaccurate,” the agency said in a written statement. “Reports of indiscriminate computer exploitation operations are simply false.”